I feel your frustration man, I'm currently playing with a band, the guitar players are solid and the singer is quite good, the bassist actually has really nice technical skills and is pretty creative...but sometime his timing is so off and he can't seem to grasp the concept of playing for a song, more than one time we'd be playing covers and he'd go off on a bass fill right in the middle of the verse, it's just so annoying! And it totally kills the vibe me and the other musicians are establishing! His timing wanders and he often starts either late or early when we transition to different parts of the song, and what gets me is that he's a very good player and the nicest guy ever, I don't know why he has these problems but sometimes it's just really frustrating playing a song and hearing it being butchered by the guy right next to you.